The goal of this protocol is to investigate the neurocognitive underpinnings of the emotional dysfunction linked to childhood behavioral disturbance; in particular, extreme conduct disorder but also attention deficit and hyperactivity disorder (ADHD). The functional hypotheses that we are testing with both neurocognitive and neuroimaging paradigms are that: (1) extreme conduct disorder, but not ADHD, is associated with dysfunction in the formation and operational use of, stimulus-punishment and to a lesser extent stimulus-reward association information; and (2) that ADHD, but not extreme conduct disorder, is associated with impairment in executive systems related to the representation and execution of task demands. At the anatomical level, we anticipate reduced activation of emotional related systems in children with extreme conduct disorder during response selection and emotional impact tasks (in particular, reduced activation of the amygdala, regions of orbitofrontal cortex and anterior cingulate). We anticipate that the neural response of children with ADHD during these tasks will be less anomalous. We anticipate that the neural response of children with ADHD during the performance of response control tasks to be anomalous (with considerable greater recruitment of anterior and posterior compensatory systems).